IOT is the next technology transition where devices allow us to sense, control and manage the devices by making them smarter and connecting them through an intelligent network.
If you look at the building blocks of IoT there are four main blocks 1) Sensors or things or Edge as you may call it 2) The Local Network; this can include a gateway, which translates proprietary communication protocols to Internet Protocol 3) Internet 4) Back end services.
The local network or the network that connects the “things” and places them on the internet is what we will focus today. Choosing the right communication technology is crucial to the success of building an efficient IOT system.
There are many choices available like cellular, Wi-Fi, ZigBee, Z-Wave, En-Ocean, 6LoWPAN and LPWAN. Most of these technologies except cellular and LPWAN are mostly suited for short range communication typically an indoor kind of application. IOT connects millions of sensors to the internet. For connecting these devices to internet and to be able to control and manage from anywhere would require us to use either cellular or LPWAN.
Here is a simple comparison of various IOT networks available and their distinctive features.
|Long Range||Yes||Yes||No||No||Limited 1.5Km||Yes|
|Tx Current Consumption||500-1000mA||600-1100mA||19-400mA||34mA||35mA||20-70mA|
|Operating Battery Life||2-4 hours||2-3 hours||2-8 hours||60 hours||Variable||10 to 20 years|
Long Range, Low power consumption , long battery life and low cost are the key factors which make LPWAN ideal network of choice for IOT. Lets dig a bit deeper into this.
In a typical IOT implementation there could be multiple sensors which could be sensing and transmitting the data. These are readings like the temperature or moisture level etc. which are short and simple message. For examples the Sensors in the factory floor sending data or sensors in the crop field sending the moisture level or location information send by fleets.
Using cellular for transmitting these simple message is overkill. It consumes more power and it is going to be costly. Cellular connections for streaming video, games, and conversation require relatively huge bandwidth compared to the simple status reports that will make up the bulk of Internet of Things transmissions.
The other challenge in an IOT application is the power consumption. LPWAN consumes extremely low power and can operate for years on a battery.
LPWAN provides long range communication, consumes low power and costs very less compared to a cellular network. Many service providers are already considering LPWAN.
What is LPWAN?
LPWAN stands for Low Power Wide Area Network. Long Range, Low Power and Low data throughput are the key characteristics of LPWAN. LPWAN sits in a sweet spot of IOT – Long range and Low bandwidth.
Some of the characteristics of LPWAN
|Spectrum||Un licensed <1GHz, 2.4GHz|
|Long Range||10s Km|
|Battery Life||Upto 20 years|
|Low Bandwidth||Upto 100Kbit/s|
|Low Chip cost||<$5|
|Low subscription Costs||<$10|
LPWAN typical use cases involve long range communications even in dense urban areas or Remote application requiring long battery life. Examples would include Smart city, smart lighting, smart metering, smart factory, Smart grid, Smart agriculture.
There are multiple long range low power networks evolving like SIGFOX, LoRA, WAVIOT. Ingenu, weightless-N.
LoRA and Sigfox are in the top of LPWAN lists with good hardware availability and maturity. Both companies have different technologies and business model but their goal is to make more and more mobile network operators to adopt their technology.And the comparison between them are for another blog.
For now it looks like LPWAN will be leading the way for IOT networks but if 5G comes with a bang to take IOT head on then the table could turn. Only time will tell!